Method of electroplating a chain

ABSTRACT

A method of electroplating a chain comprising electroplating the chain while making the same pass over some sprockets arranged in a plating solution. The chain may be endless for being recirculated in and out of the plating solution. The sprocket arranged in the plating solution may have an inclined shaft. A pair of the sprockets in the plating solution may have compensatingly inclined shafts for completely plating constituents of the chain along clearances formed between these constituents. Arrangements for carrying out the method are also disclosed.

United States Patent Araya [451 Mar.28,1972

[54] METHOD OF ELECTROPLATING A CHAIN [72] Inventor: Kumakichi Araya, No. 2, Doishaji Sekimachi, Kaga-shi, Japan [22] Filed: Apr. 26, 1968 21 Appl. No.: 724,562

[30] Foreign Application Priority Data Sept. 25, 1967 Japan ..42/6l239 Sept. 7, 1967 Japan ..42/57000 [52] US. Cl ..204/28, 204/24, 204/206 [5 1] Int. Cl ....C23b 5/58, C23b 5/48, BOlk 3/00 [58] Field 01 Search ..204/28, 24

[56] References Cited UNITED STATES PATENTS 3,046,214 7/1962 Ross ..204/28 FOREIGN PATENTS OR APPLICATIONS 1,187,452 2/1965 Germany Primary Examiner-John H. Mack Assistant Examiner-T. Tufariello Attorney-Michael S. Striker [57] ABSTRACT A method of electroplating a chain comprising electroplating the chain while making the same pass over some sprockets arranged in a plating solution. The chain may be endless for being recirculated in and out of the plating solution. The sprocket arranged in the plating solution may have an inclined shaft. A pair of the sprockets in the plating solution may have compensatingly inclined shafts for completely plating constituents of the chain along clearances formed between these constituents. Arrangements for carrying out the method are also disclosed.

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ATTORNEY METHOD OF ELECTROPLATING A CHAIN BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is concerned with the electroplating of chains, and particularly of transmission chains. This invention would be classified into class 59 or class 204 in the U.S. Patent Classification.

2. Description of the Prior Art l-leretofore, such constituents as the inside link plate, the outside link plate, the pin, the bush, etc., for the transmission chain, for example, the roller chain, the bushed roller chain, the bushed chain, etc., are in general subjected to such heat treatments as hardening, tempering, hard facing etc., for improving their mechanical strength, abrasion resistance, acid resistance, etc. Alternatively, an anticorrosive oily agent is applied thereto. It is also well known that they are electroplated for improving their anticorrosion. It is well known that such constituents of a chain as outside link plates, inside link plates, chain pins, chain bushes, etc. are each electroplated as a single element before they are assembled into a chain. Alternatively, a chain constituted with the above constituents is electroplated by immersing in a plating bath. Due to these manners of electroplating, the constituents of the chain plated before the assembling operation are apt to be damaged by peeling and staining the plated film when the constituent is forcedly fitted in with another with a proper interference for the assembling operation. Furthermore, even if the constituents have been plated with sufficient adhesion as the elements and the peeling and staining have been avoided during the forced fitting of an element with another, it is difficult to unify the color and luster of the elements of an assembled chain. In case of plating an assembled chain, not only it is troublesome to handle a lengthy chain when the same is immersed into and taken out of a plating bath, but also it is extremely difficult to secure a proper strength of the chain by virtue of the hydrogen embrittlement occuring during the plating operation. The hydrogen embrittlement is explained as follows. The acidic washing is necessary for a material to be plated prior to the plating operation. In said operation, the washed material serves as a cathode and absorbs and accumulates hydrogen on said material, accordingly numerous fine pits arise on said material. Therefore, said material becomes porous and is apt to be subjected to damage on its surface. This fact is the hydrogen embrittlement. In addition, practically speaking, it is extremely difficult that, in case of plating an assembled chain, even such parts as the joint of a bush with an inside link plate or a pin with an outside link plate, the clearance between a roller and a bush, etc. are uniformly plated.

Furthermore, if the material is pickled by such as sulfuric acid or io cathode-electrolytically cleaned prior to the plating operation for rendering a uniform color and luster all over the chain and providing a film having an excellent adhesion, it is unavoidable to bring on such drawbacks that the material is made weak, and particularly the peripheral edge of the holes of the inside link plate and the outside link plate is broken or apt to be broken, disturb smooth driving action of the chain.

For the purpose of employing a chain, for example, in case of conveying such products as foodstuffs, pharmaceuticals, clothing, etc., the chain is required to be sanitary and, in addition, anticorrosive, so that stainless steel, synthetic resin, etc. are adopted as the material for forming the chain. However, such drawbacks as difiiculty in precise working of the chain and increasingly expensive cost of the materials are inevitable.

SUMMARY OF THE INVENTION Briefly stated in accordance with one aspect of this invention, there is provided a method of electroplating a chain,

. comprising the steps of providing a bath containing a plating solution in which at least a rotatable carrying means is provided and above which at least a similar means thereto is provided, making the chain pass over these rotatable carrying means, and plating the chain while driving by at least one of these rotatable carrying means. In accordance with this invention, for carrying the method into effect, some rotatable carrying means are provided above the plating solution and some rotatable carrying means are provided in the plating solution, the chain passing over these rotatable carrying means in the manner of the endless belt, and driven by at least one of these carrying means, and at least one of these rotatable carrying means serving to feed electricity for plating. Further in accordance with this invention, the shaft of one of these rotatameans for the electroplating of the chain, whereby it is possible to adhere the plated coatings sufiiciently even on the engaging portions of the constituents of the chain with each other.

Still another object of this invention is to provide a means for the electroplating for the chain, whereby the chain is protected from the hydrogen embrittlement and neither damaged nor stained, and which is simplified in construction.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood and other objects and additional advantages of the invention will become apparent upon perusal of the following description taken in connection with the drawings, in which:

FIG. I shows a part of a bushed roller chain with a fragmentary section;

FIG. 2 is an enlarged sectional view of a part of an inside link plate perforated;

FIG. 3 is a still enlarged sectional view of a part of an inside link plate, a bush being fitted in with the same;

FIG. 4 is a longitudinally sectional view of an embodiment of this invention;

FIG. 5 is a vertically cross-sectional view thereof taken along lines X-X of FIG. 4;

FIG. 6 is a vertically cross-sectional view thereof taken along lines Y-Y of FIG. 4;

FIG. 7 is an enlarged explanatory view corresponding to FIG. 5, in which the engagement of the chain with the sprocket is illustrated; and

FIG. 8 is a perspective view of another embodiment of this invention.

PREFERRED EMBODIMENTS OF THE INVENTION Referring more particularly to the drawings, the preferred embodiments of this invention will now be described; however, this description will be understood to be illustrative of the invention and not as limiting it to the particular constructions shown and described. For the sake of explanation, a construction of a bushed roller chain will be at first described, as a representative of various chains.

There is a pair of inside link plates 1 oppositely arranged with each other. A pair of outside link plates 2 are laminated outside the inside link plates 1, respectively. A bush 3 is fitted in a hole h perforated through the inside link plate 1 and fixed thereto, as shown in FIGS, 2 and 3. A roller 4 is rotatable fitted on the outer cylindrical surface of the bush 3 between the two inside link plates 1, as shown in FIG. 1. A pin 5 is rotatably inserted into the bush 3, of which the both ends are fixed to'the outer link plates 2, respectively. In the assembling operation of the operative chain C thus constructed, the peripheral wall of the hole h is plastically deformed when the bush 3 is inserted therein. In order to prevent the plastic deformation, it is necessary to provide a hole h having a diameter d which is somewhat smaller than a required diameter D, as

shown in FIG. 2. The bush 3 is inserted into the hole h having the diameter d, therefore there are in advance formed edgeclearances f and 8 along both side edges of the peripheral wall of the hole h, so that it is to be seen that there are edgeclearances f and 3 along a part of the fitting surface of the bush 3 with the inside link plate 1. Such an edge-clearance is necessary to be considered in connection with the following description of the embodiments of this invention.

At least an anode plate p is held in the suspended state in a plating bath T containing a plating solution L. Two shafts 6 and 7 are arranged inwards from the anode plate p in the plating solution L. Three shafts 8, 9, and are arranged above the bath T. These three shafts are arranged horizontally and rotatable. The shafts 6 and 7 are rotatable but not horizontally arranged. They are inclined from the horizontal in vertical planes parallel with each other, respectively, and are oppositely and correspondingly inclined to each other. Five sprockets 6s, 7s, 8s, 9s, and 10s are fixedly mounted on these shafts 6, 7, 8, 9, and 10, respectively. A pair of rotatable shaft 11 and 12 are arranged in parallel with and almost in horizontal alignment with the shafts 8, 9, and 10 and supported rotatably on a pair of stands 14 and 15 arranged outside both longitudinal ends of the bath T, respectively. A pair of drums lln and 12n are fixedly mounted on the shafts l1 and 12, respectively. Either of the drum lln or 12n is a winding drum and the other is a rewinding drum. The shaft for the winding drum, for example, the shaft 12 is adapted to be driven by a motor (not shown).

A chain C to be plated is made to pass over the sprockets 8s, 6s, 9s, 7s, and 105 from the drum lln for rewinding the chain C to the drum l2n for winding the same, with tension. By energizing the motor, the chain C is made to pass through the plating solution L. The anode plate p is connected with the anode of a source of electricity (not shown) by means of a lead 16 while the shaft 10 is connected with the cathode of the source of electricity by means of a lead 17.

Referring now to FIG. 8 showing another embodiment of this invention, there is provided a U-shaped conductive bar 20 which is supported horizontally by a suitable means (not shown) inside a bath T containing a plating solution L. Some anode plates p1, p2, p3, etc. are suspended from the bar 20 at predetermined intervals one after another. There are two rotatable shafts 21 and 22 arranged inside the plating solution L, on which two sprockets 21s and 22s are fixedly mounted, respectively. There are two rotatable shafts 23 and 24 arranged above the plating solution L, on which two sprockets 23s and 24s are fixedly mounted, respectively. Each of the two sprockets 23s and 24s are fixed to an end of each of the shafts 23 and 24. A chain C which has been formed endlessly is made to pass over these four sprockets 21s, 22s, 23s, and 24s. The shaft 23 is driven by a motor (not shown) by the medium of a driving shaft 25. The conductive bar 20 is connected with the anode of a source of electricity (not shown) through a lead 26, while the shaft 24 is connected with the cathode of the source of electricity through a lead 27.

In connection with the embodiment illustrated in FIGS. 4 through 7 again, the chain C to be plated has been wound up on the drum lln shown leftwards in FIG. 4 and is rewound therefrom rightwards. Passing over the sprockets 8s, 6s, 9s, 7s, and 10s, the chain C is wound up on the drum I2n by driving the shaft 12 of the drum l2n by a motor (not shown), as shown rightwards in FIG. 4. The chain C is plated while being moved through a bent course in the face of the anode plate p in the plating solution L so that the plated chain C is wound up by and on the drum l2n continuously and automatically.

The plating solution L is automatically stirred by virtue of the passage of the chain C inside the plating solution L while guided by the five sprockets 8s, 6s, 9s, 7s, and 10s, ending in to unify the concentration of the plating solution L throughout the bath T, and, in turn, to produce a plated chain having a plated coating of uniform color and brightness without stain. Furthermore, when said chain is electroplated while being driven through the bath, hydrogen which is generated on the surface of said chain escapes immediately and continuously from said surface. Therefore, hydrogen does not adhere on said surface substantially and there are not apprehensions that the strength of said chain lowers. This fact prevents to increase electric resistance of the material on the cathode side, accordingly, electric current is not subjected to improper resistance and electric power is not wastefully consumed. in addition, by virtue of the arrangement of the sprockets 6s and 7s which are mounted on shafts inclined from the horizontal as shown in FIGS. 5, 6 and 7, a clearance 14 between the outside link plate 1 and the inside link plate 2 of a side of the chain C is filled with theplating solution L during the passage of the chain C over the inclined sprocket 6s as shown in FIG. 7, while the other clearance (not shown) between the outside link plate 1 and the inside link plate 2 of the other side of the chain C is filled with the plating solution L during the passage of the chain C over the sprocket 7:, so that it is easily possible to plate even such clearances as above with a coating having a uniform color and brightness within a short period automatically. There are also provided the edge clearances f and g at the both side edges of the peripheral wall of the hole h, therefore when the bush 3 is inserted into said hole h, the damage by the plastic deformation does not occur on said portions. As the sprockets 6s and 7s are oppositely inclined each other to the surface 13 of the plating solution L, the plated film is uniformly coated even on such narrow portions as the edge clearances f and g. Therefore the sufficient plating operation may be performed so that an unplated portion does not occur on said chain.

It is possible that a plating process is included in a producing process of an article without any excessive time and labor inherent to any outside order for the plating work only, because it is possible to provide a plating line in a plant in accordance with this invention. Considerations in connection with the preciseness in working, the embrittlement of the material and the existence of any damage on the surfaces of members of the chain need not be substantially paid during the assembling operation of the chain by virtue of this invention. In addition, thus a chain having a strong coating may be easily obtained. The apparatus for carrying out this invention is extremely simple as a whole so that it is possible to carry out the method in accordance with this invention very easily without a substantial expense and labor for the provision.

In connection with the embodiment illustrated in FIG. 8 again, the endless chain C is plated while being recirculated over the sprockets 21s, 22s, 23s, and 24s, when the sprocket 23s is driven by a motor by the medium of the driving shaft 25 and the plating solution L is energized through the anode plates pl, p2, etc. and the sprocket 24s. By virtue of the stirring action due to the recirculation of the chain over the four sprockets, the concentration of the plating solution L is maintained always at a constant rate similarly to the embodiment illustrated in FIG. 4, so that a coating having an uniform color and luster may be obtained on a chain. It is possible to feed current from either of the sprockets 23s and 24s. It is also possible to provide an intermittent motion mechanism comprising a ratchet and a pawl (not shown) for driving the chain intermittently. By means of this, it is possible to adjust the thickness of the coating to be produced on the chain.

In these embodiments as shown in FIGS. 4 and 8, it is possible to substitute grooved pulleys for the sprockets 6s, 7s, 8s, 9s, 10s, 21s, 22s, 23s, and 24s as a whole or partly.

While preferred embodiments of this invention have been illustrated and described in connection with a bushed .roller chain as the product to be plated, modifications thereof and applications thereof to other chains, such as a bushed chain, a roller chain, etc. will readily occur to those skilled in the art. It should be understood therefore that the invention is not limited to the particular arrangement and method disclosed but that the appended claims are intended to cover all modifications and applications which do not depart from the true spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A method of electroplating a chain, comprising the steps of providing a bath of plating solution; supporting longitudinally spaced portions of the chain upwardly above said bath, and allowing a loop of the chain intermediate said portions to dip into the bath so that its increments are oriented in a vertical first plane; advancing the chain longitudinally of itself so that successive increments thereof form said loop and travel through said bath; plating said successive increments of the chain while they travel through said bath; and alternately changing the orientation of said increments in said loop from said vertical first plane to respective oppositely inclined second planes, to thereby facilitate access of said solution to different portions of said increments.

2. A method as defined in claim 1; further comprising the steps of positioning anode means in said bath; connecting said anode means with one pole of a source of electrical energy; and connecting said chain at least at one of said spaced portions with the other pole of said source of electrical energy.

3. A method as defined in claim 1, wherein the step of advancing said chain comprises moving the same continuously longitudinally of itself.

4. A method as defined in claim 1, wherein the step of advancing said chain comprises moving the same intermittently longitudinally of itself. 

2. A method as defined in claim 1; further comprising the steps of positioning anode means in said bath; connecting said anode means with one pole of a source of electrical energy; and connecting said chain at least at one of said spaced portions with the other pole of said source of electrical energy.
 3. A method as defined in claim 1, wherein the step of advancing said chain comprises moving the same continuously longitudinally of itself.
 4. A method as defined in claim 1, wherein the step of advancing said chain comprises moving the same intermittently longitudinally of itself. 